1. Technical Field
This invention relates generally to a connector for connecting transmissions paths and, more particularly, to a right-angle interconnect for providing signal transitions between high frequency signal transmission paths such as those provided by stripline circuit traces found on circuit boards.
2. Discussion
Transmissions paths are commonly used to carry and distribute signals such as those found in the radio and microwave frequency range. Interconnects are frequently employed to connect one transmission path to another transmission path for purposes of providing signal transitions therebetween. For instance, interconnects are often used to provide external electrical connections between, for example, coaxial cables and circuit traces located on a circuit board. In other instances, interconnects are often used to form an electrical connection between a pair of circuit traces on adjacent circuit boards.
Prior conventional coaxial cable interconnects have been used to provide signal transitions between a first transmission path in a coaxial cable and a second transmission path. These conventional interconnects have generally included a simple soldering splice formed directly between the inner conductor of the coaxial cable and the circuit traces. While such interconnects have served to a limited extent, they generally have experienced rather poor signal performance, especially at high frequencies. In addition, while solder joints have commonly been employed in the past to form an adequate connection between the two conductors, solder connections generally involve additional costs which includes costs incurred for assembly labor and materials. Furthermore, the reliance on solder joints may also lead to limited reliability and inflexibility.
More recently, in lieu of the prior conventional coaxial cable interconnects, commercially available interconnect systems have been used to electrically interface circuit traces. These commercially available coplanar interconnects are generally known throughout the field as "SMA" type connectors which may include a flange that surrounds the circuit and a cylindrical center pin that contacts the circuit. Existing "SMA" type connectors include a coplanar interface known as an end launch and a ninety degree (90.degree.) interface known as a surface launch such as the type manufactured by Omni-Spectra. The surface launch interconnect provides a right-angle coax connector to stripline connection. However, like prior conventional systems, the commercially available right angle interconnects generally exhibit poor performance at high frequencies and do not offer the flexibility that may be desired with modern day electronic systems, especially those operating in the RF/microwave frequency range and above.
While existing right-angle interconnect systems have attempted to achieve signal transitions for modern day electronic systems, such interconnects have typically exhibited rather poor electrical performance at higher frequencies, especially those approaching 10 GHz and higher. This is generally due to the sensitive characteristics of high frequency signals which may result in poor voltage standing wave ratio (VSWR) and propagation and launching of unwanted higher-order transmission line modes within the associated circuitry. In addition, commercially available interconnect systems are considerably large in view of modern day electronic systems. Accordingly, the poor performance and large size are undesirable characteristics exhibited by existing interconnects when used with high-frequency state-of-the-art RF/microwave electrical systems which are currently available and those that will be available in the future.
It is therefore desirable to provide for a more flexible solderless interconnect for providing enhanced performance high frequency signal transitions between transmission paths. More particularly, it is desirable to provide for an enhanced profile solderless interconnect for achieving high frequency signal transitions between a stripline circuit trace and a coaxial cable. In addition, it is further desirable to provide for such a solderless interconnect to achieve enhanced performance high frequency signal transitions between stripline circuit layers within a multiple-layer circuit board. Furthermore, it is desirable to provide for such interconnects which may achieve wide instantaneous bandwidths and lightweight, low cost, low-profile packaging for use with RF and microwave electronic systems.